Erasing instrument



y 0, 1963 M. HERTZ 3,099,251

ERASING INS'IYRUMENT Filed Jan. 1'7, 1962 INVENTOR,

,1 i I W United States Patent 3,099,251 ERASING INSTRUMENT Michael Hertz, 821 National Press Bldg., Washington 4, D.C. Filed Jan. 17, 1962, Ser. No. 166,797 1 Claim. (Cl. 120-38) The invention relates to erasing instruments and in particular to means for incrementally feeding an eraser out of a holder as it is being used up in order to provide fresh material.

It is an object of this invention to provide simple means for feeding the eraser out of the holder by mere rotation of the holder with respect to a support for the holder.

For a full understanding of the invention, attention is directed to the following specification and claim when taken in conjunction with the accompanying drawing in which FIG. 1 is a plan view of a pencil-eraser combination instrument embodying the invention, part being shown in section.

FIG. 2 is a view on the line 22 of FIG. 1 looking in the direction of the arrows.

FIG. 3 is a view, mostly in section, of the upper portion of the holder and eraser showing a modified form of the invention.

FIG. 4 is a View on the line 44 of FIG. 3 looking in the direction of the arrows and FIG. 5 is a plan view of a modification of a portion of the eraser advancing means, a surrounding sleeve being shown in section.

Now referring to the drawings with greater particularity, in FIG. 1 there is shown a pencil-eraser combination indicated generically as 10.

The combination comprises an instrument having a cylindrical tube 12 to function as a support for the pencil and eraser mechanism and for storage of writing leads 14 therein. Within the tube is conventional lead propelling mechanism (not shown). For the purpose of driving the propelling mechanism, the tube 12 has rotatably mounted thereabout a lead driving sleeve portion 16 which is tapered toward the lower end, as at '18, the lower tapered end drivingly engaging a portion of the lead propelling mechanism within the tube 12, as is conventional in the art. Since the lead propelling mechanism forms no part of the invention, it is not illustrated. A metal tip 20 is screwed onto the lower end of the lead propelling mechanism and butts up against the sleeve 16 to prevent it from moving downwards on the tube 12 and to guide the lead 14 thru the lower end thereof. Upward motion of the sleeve 12 is prevented by a finger piece 22 in the form of a sleeve fixedly secured to the tube or support 12 intermediate the ends thereof in any suitable manner, as by cement. Thus, by grasping the finger piece 22 and rotating the driving sleeve 16-18, the writing lead may be advanced and retracted, in a manner well known in the art.

The eraser advancing mechanism will now be described.

The magazine tube, or support 12, extends above the finger piece 22 and it may be slotted, as shown 'at 24, to allow the tube to frictionally and resiliently hold telescoped thereover, cylindrical eraser drive sleeve 26. The sleeve 26 is preferably metal lined as indicated at 28 for better wear of parts and has atiixed thereto a pocket clip ice 29. Frictionally held within the upper end of the metal lined sleeve for rotation and translation therein is a very long cylindrical eraser '30 of rubber or like material, suitable for erasure of writing lead or ink marks. The bottom of the eraser has afiixed thereto a sheet metal cap 32. The metal cap is generally cup shaped with Ian inturned lip 34 firmly engaging the eraser and a reentrant bottom or pocket 36 of non-circular form pressed upwardly into the cap. The reentrant bottom is preferably polygonal in plan view, as square, to seat on a complementary contoured head 38 of a screw 40 threaded into an inverted cup 42 seated by means of an extruded flange 44 on the upper edge of the tube '12. The cup has an integral skirt 46 frictionally held within the tube 12. It will be seen that when the eraser is within the sleeve 26 and the cap is seated on the head of the screw, a rotation of the eraser will cause the screw to thread with respect to the inverted cup 42, the screw then moving longitudinally of the cup and tube 12 and, in one direction of motion, thrusting the eraser 30 upwardly, as seen in FIG. 1. The skirt seated in the upper end of tube 12, because of its frictional engagement and because of the threading of the screw in the cup, does not rotate in the tube and therefore the inverted cup does not rotate. The rotation of the eraser elfected by rotating the upper sleeve 26 while holding the finger piece 22. Thus, when the exposed end of the eraser is used up, the eraser may be advanced by properly rotating the sleeve 26 relative to the finger piece 22, the eraser then rotating with the sleeve 26, and advancing the screw upwardly by the reason of the non-circular portions of the screw 40 and cap 32 being in engagement, thereby also forcing the eraser upwardly.

After the eraser has been used up to the extent desired, the sleeve 26 may be pulled ofi from the tube 12 and the now advanced screw 40 manually threaded down into the inverted cup 42.

The spent eraser portions are then removed from the sleeve 26 and a new eraser with aflixed cap is inserted into the sleeve and thrust downwardly thereinto. When the sleeve 26 is then replaced in the tube 12, the cap 32 will engage the head 38 of the screw. If the cap and head of the screw do not immediately drivingly interengage, downward pressure on the eraser and rotation of the sleeve 26 in a direction to advance the eraser will bring about coupling of the cap and screw. Use of the eraser will also eifect coupling because in erasing some turning of the eraser in the sleeve 26 will take place notwithstanding the frictional engagement therebetween.

In a modification of the invention, the sheet metal cap 50, shown in FIGS. 3 and 4, has prongs 52 struck out from the reentrant bottom of the same, these prongs embracing the sides of the head 38 of the screw. The prongs are arranged along the side of a regular polygon to engage the sides of a similarly shaped polygonal head on the screw. Specifically four prongs are shown.

In FIG. 5 there is shown a modified form of skirt portion 54 on the inverted cup. In this form of the invention, the skirt portion is provided with longitudinal flutes 56 directed inwardly toward the center of the cup and cooperating with complementary inwardly directed flutes 58 on the upper portion of the tube or support 12.

Having thus described the invention, what is claimed is:

An eraser instrument comprising a support, a coupling element in the form of a screw threaded into the upper portion of the support, a sleeve having a cylindrical inner surface rotatable about the support and a long cylindrical eraser frictionally fitted within the cylindrical surface of the sleeve, said eraser having a second coupling element in the form of a cap 1aflixed to the eraser, one of said coupling elements having a non-circular pocket and the other element having :a non-circular projecting portion fitting into the pocket, the two portions constituting the sole means for coupling together the cap and the screw, whereby on rotation of the sleeve with respect to the support, the eraser will move longitudinally of the sleeve, and whereby a spent eraser may be replaced in the sleeve by straight line coupling action.

References Cited in the file of this patent UNITED STATES PATENTS Sloan July 27, 1897 Kilstrom July 21, 1914 Balch May 28, 1918 Hasselquist Dec. 12, 1939 Teft et a1 June 16, 1942 Savoie Aug. 22, 1944 Robbins Nov. 28, 1950 Hansen Oct. 14, 1952 Hansen Nov. 10, 195-3 Master-nick Nov. 12, 1957 

